What is the European standard system for steel materials

European standard (EN) is a unified metal standard system in European countries. Although EN standard is widely accepted and effectively applied in European countries, the so-called "abandoned" national standards, such as German DIN standard, British BS standard, French AFNOR standard and Italian UNI standard, often appear in various documents.

DIN standard is issued by German Deutsches Institut für Normung. All German steel materials standards and material names begin with DIN and are followed by letter or number codes. For example, DIN 40NiCrMo66 or 1.6565 is nickel chromium molybdenum steel, which contains 0.35-0.45% C, 0.9-1.4% Cr, 0.5-0.7% Mn, 0.2-0.3% Mo, 1.4-1.7% Ni, 0.035% S; DIN 17200 1.1149 or DIN 17200 Cm22 is non re vulcanized carbon steel, which contains 0.17-0.24% C, 0.3-0.6% Mn, 0.02-0.035% S and maximum 0.4% Si.